There is a clear trend to create safe connections to websites, wich apply to forums in a special way.

Beside testing php7 I also tested the free offer of the "Let´s encrypt initiative", which recommends to use CERTBOT (https://certbot.eff.org/)
It requires you to have root access on your server, just to say that clear.

Anyway, the process outlined is pretty straightforward. CERTBOT asks you about Webserver and System, and then gives detailed instructions.
Around 5 or 10 minutes with Debian including installation of some modules required.

You then only have to change the web address in your Fudforum admin to the new https://, so even coming-in with http:// everyone is switched to https:// with the first click